Aviation safety investigations & reports

Hydraulic system malfunction, return and evacuation, involving Airbus A330, VH-EBC, 94 km west-north-west of Sydney Airport, New South Wales, on 15 December 2019

Investigation number:
AO-2019-073
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final

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What happened

On 15 December 2019, an Airbus A330-202 aircraft, registered VH-EBC and operated by Qantas Airways, departed Sydney, New South Wales on a scheduled passenger service. About 7 minutes after departure, the flight crew were alerted to a problem with one of the aircraft’s 3 hydraulic systems. The flight crew followed the required checklists and decided to return to Sydney. Following an uneventful landing, the flight crew stopped the aircraft on a taxiway. Shortly after, the auxiliary power unit (APU) was started and the bleed air selected on to maintain air conditioning in the aircraft cabin, and the aircraft was towed to the terminal.

After the aircraft arrived at the terminal, a haze/smoke began to form in the cabin and flight deck, followed by passengers and crew experiencing physical symptoms. After consultation with the customer service manager and the first officer, the captain commanded an evacuation.

The first of 2 aerobridges had already been connected to the aircraft when the evacuation command was given. At this time, some passengers were already standing and had retrieved their cabin baggage. Slides were successfully deployed on 3 exits, and the second aerobridge was then connected to another exit. Two of the other 3 exits were not used and the slide was not successfully deployed at the other exit. Of the passengers who used the escape slides, one received serious injuries and 5 received minor injuries.

What the ATSB found

The rudder servo flexible pressure hose from the aircraft’s green hydraulic system ruptured during the flight, which resulted in a hydraulic fluid leak towards the rear of the aircraft. The rupture was due to a combination of corrosion and fatigue cracking of the stainless streel braid in the hose.

Following a significant period of time after landing, the hydraulic fluid was ingested into the APU air intake, which led to atomised hydraulic fluid contaminating the aircraft cabin and flight deck through the air conditioning system. Although cabin crew members had smelt an odour they thought was related to the hydraulic system failure or similar fumes prior to arriving at the terminal, they did not convey this information to the flight crew.

The evacuation occurred at a unique time when cabin crew members had completed their shut-down duties and the aircraft was at the terminal with all the doors disarmed. Although cabin crew had covered a similar scenario during their initial training, in subsequent evacuation training the doors would always be armed. This may have been contributory to 2 of the cabin crew not rearming their door prior to opening it during the evacuation. In contrast, 2 of the other cabin crew members had verbalised what they would do if they were required to evacuate and were successful in executing their procedures without hesitation.

Some passengers (who used the aerobridges or the slides) retrieved their cabin baggage after the evacuation command was given. In addition, some passengers who evacuated using the slides carried their cabin baggage down the slides. As a result, the evacuation was delayed and the risk of injury to themselves and others was increased. The ATSB also found that information provided to passengers via the safety briefing and during the evacuation about what to do with cabin baggage in an evacuation and the use of escape slides was limited and inconsistent.

In addition, the primary evacuation commands practiced by cabin crew to instruct passengers in an evacuation did not include phrases such as 'leave everything behind' and 'jump and slide'. Consequently, passengers would generally not receive specific guidance until they reached an exit, which could potentially slow an evacuation. The operator also did not have a procedure for a rapid disembarkation, which would allow for rapid deplaning at a slower and more controlled pace than an emergency evacuation.

What has been done as a result

Qantas introduced a procedure for A330 flight crew to refrain from turning the APU bleed on until an engineering inspection had occurred following a hydraulic system leak. The operator also introduced a periodic replacement program for the pressure supply line to the hydraulic servo for all 3 hydraulic systems.

In addition, Qantas introduced periodic training that required cabin crew members to physically demonstrate the procedures for an evacuation at the terminal. It also amended its passenger safety briefing video showing passengers how to descend the escape slide. The operator advised it was also looking to incorporate ‘leave everything behind’ into its primary evacuation commands, and developing a procedural framework for the rapid disembarkation of passengers in circumstances where an evacuation and the use of escape slides may not be necessary.

Safety message

The management of passengers in an emergency situation is the last line of defence in avoiding injury and fatalities, therefore it is important that passengers are well informed through the provision of sufficient and accurate communication about what they may be required to do.

The timing of this occurrence highlights the necessity for crew members to remain prepared to react to an emergency at any time, until everyone has disembarked the aircraft. Using a method such as the silent review prompts cabin crew members to mentally rehearse emergency procedures, which ensures they are ready to act in case of an emergency.    

Communication between the cabin crew and flight crew is essential in abnormal situations, and it is important for information to be relayed as soon as it becomes available. Cabin crew should be trained to recognise and report to the flight crew any unusual smells, sounds and sights, including the use of common terminology to describe odours. 

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The occurrence

Context

Safety analysis

Findings

Safety issues and actions

Sources and submissions

Glossary

Appendix A – Hydraulic system supply overview

Appendix B – Operator cabin crew land evacuation impact drill

Appendix C – Research and previous occurrences related to rapid disembarkations

Appendix D – Airbus response to recommendation SR49/2016

Australian Transport Safety Bureau

Summary

The ATSB is investigating a hydraulic system malfunction and subsequent evacuation involving an Airbus A330 aircraft, registered VH-EBC and operated as Qantas flight 575 (QF575), at Sydney Airport, New South Wales, which occurred at about 1015 local time on 15 December 2019.

The aircraft departed Sydney on a scheduled passenger service to Perth. About 30 minutes into the flight, the flight crew identified an issue with the aircraft’s green hydraulic system, and the captain decided to return to Sydney. Following an uneventful landing, the aircraft entered the taxiway. Both engines were shut down and the aircraft’s auxiliary power unit was selected on. Due to the hydraulic system issue, nose wheel steering was unavailable, and the aircraft was towed to the gate.

Soon after arriving at the gate, mist was observed in the cabin and flight deck. The captain initiated an evacuation, which occurred through the aerobridge and three escape slides. As a result of the use of the escape slides, one passenger received a serious injury, with two other passengers reporting minor injuries. Subsequent examination of the aircraft identified that hydraulic fluid had leaked from the green hydraulic system.

As part of the investigation, the ATSB will interview the flight crew, cabin crew, other relevant personnel and selected passengers. The ATSB will also analyse data from the aircraft’s flight data recorder and cockpit voice recorder and review evidence associated with the hydraulic system malfunction.

The ATSB is requesting that passengers on board flight QF575 and/or witnesses that have any information, video footage or photographs that they consider may be of relevance to the investigation to please contact the ATSB via email at QF.575@atsb.gov.au

A report will be released at the end of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant stakeholders so appropriate and timely safety action can be taken.

Safety Issues

Go to AO-2019-073-SI-03 - Go to AO-2019-073-SI-01 - Go to AO-2019-073-SI-02 - Go to AO-2019-073-SI-05 -

Passenger safety information

Qantas’s method of briefing passengers provided limited and inconsistent information about how to use the escape slides safely and what to do with cabin baggage in an emergency.

Safety issue details
Issue number: AO-2019-073-SI-03
Status: Closed – Adequately addressed

Evacuation commands

Qantas's cabin crew primary evacuation commands did not include phrases such as 'leave everything behind' and 'jump and slide'; instead, these phrases were optional. Consequently, passengers would generally not receive specific guidance until they reached an exit, which would likely slow down the evacuation.

Safety issue details
Issue number: AO-2019-073-SI-01
Status: Open – Safety action pending

Cabin crew training

Qantas's cabin crew recurrent training did not include any situation whereby a disarmed door would have to be rearmed in an emergency. This increased the likelihood that a door would be opened without the escape slide deployed, reducing the number of available exits.

Safety issue details
Issue number: AO-2019-073-SI-02
Status: Closed – Adequately addressed

Procedure for a rapid disembarkation

Qantas did not have a procedure for a rapid disembarkation, or other similar procedure that would effectively enable rapid deplaning at a slower and more controlled pace than an emergency evacuation. Therefore, the only option for rapid deplaning was an emergency evacuation utilising slides, which unnecessarily increased the risk of injuries in some situations.

Safety issue details
Issue number: AO-2019-073-SI-05
Status: Open – Safety action pending
General details
Date: 15 December 2019   Investigation status: Completed  
Time: 0851 EST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): 94 km west-north-west of Sydney Airport   Investigation phase: Final report: Dissemination  
State: New South Wales   Occurrence type: Hydraulic  
Release date: 21 June 2022   Occurrence category: Accident  
Report status: Final   Highest injury level: Serious  

Aircraft details

Aircraft details
Aircraft manufacturer Airbus  
Aircraft model A330-202  
Aircraft registration VH-EBC  
Serial number 0506  
Operator Qantas Airways Limited  
Sector Jet  
Damage to aircraft Nil  
Departure point Sydney Airport, NSW  
Destination Perth Airport, WA  
Last update 21 June 2022